Malicious PDF — malware analysis report

Static analysis result for SHA-256 559ff3f288be98af…

MALICIOUS

PDF

81.6 KB Created: 2021-08-20 00:45:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e7139278625d35b0f5a3668b7469a2f4 SHA-1: 8047b2d5c029da6c0a2f60422eeccbd78a588cce SHA-256: 559ff3f288be98afd1428e811f6cfd083c80c6f9f9be702d2b9ac5bbff1543c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous embedded URLs pointing to various websites. Some of these URLs lead to compromised CMS upload directories or disposable domains, indicating a likely attempt to lure users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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.
  • 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://mishelik.ru/userfiles/file/75427881131.pdf In PDF document text
    • https://polandpools.com/contents//files/2375040975.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2b9fd2def---35454041484.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/jn1etbflrnn6t8ao2u8h050se3/rutawanetatibaketaju.pdfIn PDF document text
    • http://loaamtran.com/files/usersfiles/files/fexirufowu.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210628021703200.pdfIn PDF document text
    • http://korytnica.net/data/files/33131188141.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/zinibewopukujamos.pdfIn PDF document text
    • http://clintonseniorhighclassof77.com/clients/e/ec/ec6cde7faca09d53f5ba1fe44cd32e38/File/sepanufidif.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/62406374869.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/7eccecac934da2197c754e65183d0596/buwuved.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f38ab494a5b---19894147505.pdfIn PDF document text
    • http://postelezmasivu-brno.com/ckfinder/userfiles/files/32784132304.pdfIn PDF document text
    • https://istanbulbalbir.com/upload/ckfinder/files/rovonuval.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edd19fdc6e5---fifazemoditikewoka.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/knlhkqd3lonthn1kklm6pivks1/sozevafomu.pdfIn PDF document text
    • http://sevimticaret.net/userfiles/file/wokeveguki.pdfIn PDF document text
    • http://djarkitek.com/temp/vinney/HTML/userfiles/file/36338719548.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=merge+multiple+sheets+in+excel+2013PDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dba8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA8 11200 bytes
SHA-256: 7b4956af4a0f5df6712e33f85904983e7ac43a2fae54539186a3951ff6bae32e
font_01_sfnt_off0000f5ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CA 16620 bytes
SHA-256: 5d907f1912d8c824bc83fd4b1461e30c8600e120b6ac38d130825fcc867e44fe
font_02_sfnt_off00012117.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12117 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1