Malicious PDF — malware analysis report

Static analysis result for SHA-256 da387235f8debb46…

MALICIOUS

PDF

86.7 KB Created: 2021-05-29 20:47:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d70113227dc8220ff16b8dd37ff5fe90 SHA-1: bfc1863efe14b342749233b44fe97e0c15994509 SHA-256: da387235f8debb469302046790376bd5380db02d7d73cf06860dfda79965e4fa
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a PDF phishing or SEO link farm. It contains numerous external links, with the primary one leading to a URL that appears to be part of a link farm. While no scripts were explicitly extracted, the PDF structure and the presence of external links suggest an attempt to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://golowaki.ru/strik?utm_term=formal+english+expressions+pdf
    • https://cdn-cms.f-static.net/uploads/4490272/normal_60468c2c688dd.pdf
    • https://cdn-cms.f-static.net/uploads/4475216/normal_6010f31e886dc.pdf
    • https://veworokog.weebly.com/uploads/1/3/1/6/131606039/kaxogem.pdf
    • https://cdn-cms.f-static.net/uploads/4482405/normal_600a782f2fc2d.pdf
    • https://cdn-cms.f-static.net/uploads/4401555/normal_6018f84e4ae57.pdf
    • https://cdn-cms.f-static.net/uploads/4484635/normal_605f0b8a653a1.pdf
    • https://cdn-cms.f-static.net/uploads/4388271/normal_6048c83431c82.pdf
    • https://newakikijako.weebly.com/uploads/1/3/4/3/134351088/pafamozofag.pdf
    • https://cdn-cms.f-static.net/uploads/4484807/normal_60281d953f85b.pdf
    • https://cdn-cms.f-static.net/uploads/4462075/normal_601feff1c706f.pdf
    • https://cdn-cms.f-static.net/uploads/4498994/normal_60342f6094e90.pdf
    • https://static.s123-cdn-static-d.com/uploads/4368975/normal_60b1b6c8a66f8.pdf
    • https://muvebodexiju.weebly.com/uploads/1/3/5/3/135311879/lowoz.pdf
    • https://bujapuvewujik.weebly.com/uploads/1/3/4/7/134702992/nejowofiwived_setisadowetewu_fenapu_dofoselasesog.pdf
    • https://static.s123-cdn-static.com/uploads/4459180/normal_60089d7070da8.pdf
    • https://cdn-cms.f-static.net/uploads/4461204/normal_6049c776ed639.pdf
    • https://static.s123-cdn-static-d.com/uploads/4401559/normal_60b0f5b7eaccd.pdf
    • https://cdn-cms.f-static.net/uploads/4526930/normal_604e5e3ef3696.pdf
    • https://static.s123-cdn-static.com/uploads/4448744/normal_5fe5d1a9a4c48.pdf
    • https://cdn-cms.f-static.net/uploads/4448547/normal_603f25dd9b030.pdf
    • https://cdn-cms.f-static.net/uploads/4404308/normal_602663b84bbcb.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/8a69c035-08c8-469f-8407-e26f631e3f77/peliculas_de_perros_y_humanos.pdf
    • https://uploads.strikinglycdn.com/files/ff8d896c-8068-4761-9ae6-9137e47607e8/paradise_lost_book_9_english_translation.pdf
    • https://uploads.strikinglycdn.com/files/10776341-4033-4055-9cfe-06915a278f33/99968401505.pdf
    • 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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011493.bin
113fe07fa1e771a053584d81c56860d74970abffe697400dcc34dd61a0b23118
pdf-font-stream PDF embedded font (sfnt) at offset 0x11493 5476 bytes
font_01_sfnt_off00012710.bin
50ceaed3c486d897eb152ccd216f383d5626484edccef40e2f6d950cc852bd95
pdf-font-stream PDF embedded font (sfnt) at offset 0x12710 10804 bytes