Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a85dbaa4df0764…

MALICIOUS

PDF

89.7 KB Created: 2021-06-09 09:48:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d2cc97f31e74e4059506b337a54d8de5 SHA-1: 040363d3b436ed9d6d1e839928f22ca9555492f2 SHA-256: a3a85dbaa4df07649205fbab73c3188c250a1eab677439a46dade5eff916a4d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document is identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as a phishing trojan. It functions as a link farm, directing users to compromised WordPress sites hosting PDF files, which in turn likely lead to further malicious content or downloads. The embedded URLs and the nature of the link farm suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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 https://cructi.ru/uplcv?utm_term=x+force+keygen+autocad+2013+64+bit
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16090723b9c5c1---12491950332.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a28317ed293---42288050327.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b190486ac46---50086185956.pdf
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ba904a43ba7---29836854920.pdf
    • http://mynigaoe.com/upload/file/20210609085335.pdf
    • https://poolpoint.be/uploads/file/31345575120.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe5d615071---36233462306.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/952c42849ed1bc10e560fe8056c4ab38/situtanewi.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/c487a24463169e774644d21230fa1cd1/jasanogizufijotu.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/dabacj35at8t895ohtamem2dn2/52698569719.pdf
    • https://advik.net/userfiles/file/resufarubesebaxo.pdf
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/h7htdlv48fcludmvgen1ts8nl5/dizopezulatilididawap.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607eab007af07---58833184377.pdf
    • http://www.ecvbrass.ch/user/web/file/bavupipopejimedepobiliw.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc6ee9c693f---81629929649.pdf
    • https://nikosdimos.gr/userfiles/file/lijoxokis.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • https://savannah.gnu.org/projects/freefont/
    • http://www.gnu.org/licenses/
    • http://www.gnu.org/copyleft/gpl.html
    • http://scripts.sil.org/OFL

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eae6.bin
ffeb89eaad713c9717385028f79c9757067aafb2c2382ea8cbab0e6efe35a425
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAE6 6744 bytes
font_01_sfnt_off0000fbce.bin
3d3ed286700cfba6fd8f8708467282dd9b2c7a99aec6872b765e538e1a2695bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBCE 5876 bytes
font_02_sfnt_off00010fd8.bin
a36eee06fef6ce219692c4ec918276ac99413e4fd1e3666e4031624f9289d620
pdf-font-stream PDF embedded font (sfnt) at offset 0x10FD8 1800 bytes
font_03_sfnt_off00011865.bin
d0a534a123e037c6aaefe3d0584523774881a3b76ecf56d8028564ea6327ef30
pdf-font-stream PDF embedded font (sfnt) at offset 0x11865 22460 bytes
font_04_sfnt_off00014b09.bin
7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71
pdf-font-stream PDF embedded font (sfnt) at offset 0x14B09 4324 bytes