Malicious PDF — malware analysis report

Static analysis result for SHA-256 41fac237dfaa171d…

MALICIOUS

PDF

79.0 KB Created: 2021-09-12 23:30:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 078aa29d0345fff7a3537e1db9e0b8e7 SHA-1: 96ab5b1e723fe7bfc1c10a72ba35947ae180c078 SHA-256: 41fac237dfaa171d1348034fda773c64bc5865b5bc4bdacb5553099714f41ef8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Several heuristics point to the document being a link farm, with many URLs hosted on disposable or compromised domains, suggesting an attempt to distribute malware or phish for information. The presence of a download button lure further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 https://nomylo.ru/uplcv?utm_term=download+naruto+senki+ultimate+ninja+storm+4+mod+apk+offline PDF link annotation
    • http://apvn.info/userfiles/file/zafizipakaf.pdfIn PDF document text
    • http://trunghungplastic.com/luutru/files/wowazodewutebano.pdfIn PDF document text
    • https://pediatricpotentialsnj.com/PP/PPpng/files/44170468718.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2bf02593c---37137921391.pdfIn PDF document text
    • https://cepatdaftargroup2.com/contents/files/penalabivujobefim.pdfIn PDF document text
    • https://vili-al.com/uploads/wysiwyg/files/gelokagetarabarenilugu.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/67215181155.pdfIn PDF document text
    • http://ksklinika.ru/ckfinder/userfiles/files/51010156903.pdfIn PDF document text
    • https://dakhoathienhoa.net/images/files/mejefudunubiburoselisulu.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/modawoxino.pdfIn PDF document text
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/39024321484.pdfIn PDF document text
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/porudobivupeg.pdfIn PDF document text
    • http://megamento.com/_UploadFile/Images/file/tedumipomonos.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/laxiridis.pdfIn PDF document text
    • http://vasekurzy.cz/userfiles/file/xotejesub.pdfIn PDF document text
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/16827640799.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9a77c26f2---14045026995.pdfIn PDF document text
    • http://coimbrasoftware.hu/images/uploads/files/58310595120.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/a28655bbde05e76e502167dfede1bb8b/53915989842.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/rejitowuwawa.pdfIn PDF document text
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE9E 17548 bytes
SHA-256: 849144dfdd4e498facfb7bd0980edff07094d2a1a9c0ffc92ef62d51e6030b16
font_01_sfnt_off0000fc12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011429.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11429 11144 bytes
SHA-256: 8a54760dfd6e818df244eced7ba723204eae29229cb324b9172d3f71362a0cc6