Malicious PDF — malware analysis report

Static analysis result for SHA-256 18f43da8ffa3f934…

MALICIOUS

PDF

95.9 KB Created: 2021-06-27 13:03:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 5b0b59f2cd83b1cb741babad5196e976 SHA-1: 269d4245c9e8f0b58eb86b31d446fefbf057fbb4 SHA-256: 18f43da8ffa3f934f5c039c2d376b4e4ef74dc93b355f4122213c4753b6bba61
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and embedded links are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/9a7f63fe3c7514f25b8ab14c9abcc452/12414154448.pdf In PDF document text
    • http://vytvarnyobchod.cz/UserFiles/File/sivejonafusi.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/bf4d283925864cd5459eb3ecb2a3e18c/90631637965.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/sfdi270gmgldrquip84af3aeps/17563994233.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160731583bcec3---zadujip.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/fb29215186ae2a938b322a50f2602d00/65381681430.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/99606727057.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/j93spcqpsq80mt8884ll4fqfp0/wedulumabus.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a16f105a452---42388136765.pdfIn PDF document text
    • https://mymango.ru/wp-content/plugins/super-forms/uploads/php/files/e5497a19870437fde57072a38cddee4c/liwalijovifotegoborimos.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16090b8823acdb---82410342689.pdfIn PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/7b5d6fe14e3411e42e42e2a4e5b3e165/bujemugam.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/etjko9lus23lj9v0rjtocdrdis/53397386498.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607499aaf34ac---28979681711.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/0d5fb722eff0db0d4ede0531bec46c2b/42351898117.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160703ea857fde---2550256082.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/jidagulenejisujatozaw.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c5b2d251dd6---waranijo.pdfIn PDF document text
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/4iriihhfagk2m6cid5qtp6ir00/nefuko.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/f53fd59755328db2f19da476d138b4e7/mabexunapotaxasegow.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609a1a4cbb47e---9021235531.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b58279ac1c5---58640488983.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/sjc4vde4j596vs0lcoq2stsdlt/lukitajopev.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/sagozugebiloguxisedu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=law+of+signs+in+multiplication+and+divisionPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001002d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1002D 10940 bytes
SHA-256: aec11a73feda9d981d6149e1b42085be21ce938839c8832f67133be761ec4ff5
font_01_sfnt_off00011966.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11966 16088 bytes
SHA-256: 21ff46de98f0902b53a5c0c946916a1dd4551bbaa4204463728281c4bc54dda8
font_02_sfnt_off00012e9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E9A 16836 bytes
SHA-256: 99ee304a5dbe46977cd68661ab00ede7cdab3f9a31ba9bd7120b95f2620ce328
font_03_sfnt_off000159a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x159A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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