Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb6fa5f118810048…

MALICIOUS

PDF

81.8 KB Created: 2021-05-29 14:29:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: c63672c5b41388756d9150cea955537a SHA-1: 25f0a44254767e01b4054dc320a834661c82edd7 SHA-256: cb6fa5f11881004846f480695a378c1e82e06ba487a7519469ab6a5597a1c8ac
186 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, and exhibits characteristics of a PDF link farm. It contains numerous external URIs, many pointing to disposable hosting services, suggesting an attempt to manipulate search engine results or distribute malicious content. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • 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.
  • 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://leonvi.ru/strik?utm_term=double+entry+accounting+exercises+pdf PDF link annotation
    • https://wubomedigupuda.weebly.com/uploads/1/3/4/6/134696881/ripowitigaziras_wedofutati_tomubetajex.pdfIn PDF document text
    • https://zejafopo.weebly.com/uploads/1/3/4/5/134505046/2332344.pdfIn PDF document text
    • https://rozinezo.weebly.com/uploads/1/3/1/6/131636990/xuwutut_wukovox_wobadoloxoziweb.pdfIn PDF document text
    • https://jonukejunuxesa.weebly.com/uploads/1/3/1/4/131409236/fb8fc923462.pdfIn PDF document text
    • https://xalonekeroritaw.weebly.com/uploads/1/3/5/3/135329664/423f50027a6f362.pdfIn PDF document text
    • https://pamibatofenowa.weebly.com/uploads/1/3/4/5/134525539/8901636.pdfIn PDF document text
    • https://jawonuvanez.weebly.com/uploads/1/3/6/0/136021807/wuzawuwiwateda.pdfIn PDF document text
    • https://fujareke.weebly.com/uploads/1/3/5/3/135391043/7582823.pdfIn PDF document text
    • https://koburuwojut.weebly.com/uploads/1/3/1/3/131378968/bbfe28f4a5d74b6.pdfIn PDF document text
    • https://kobafanosige.weebly.com/uploads/1/3/4/0/134016660/52108.pdfIn PDF document text
    • https://jabukosiw.weebly.com/uploads/1/3/0/8/130874379/c10e3fb949e.pdfIn PDF document text
    • https://vexivager.weebly.com/uploads/1/3/4/6/134634122/d74d74.pdfIn PDF document text
    • https://defusisiz.weebly.com/uploads/1/3/4/5/134599350/9807895.pdfIn PDF document text
    • https://rufukowov.weebly.com/uploads/1/3/4/6/134665675/7686768.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/ae0324c6-c208-4018-8cd0-d9dd9457d33b/survival_of_the_fittest_tab_mobb_deep.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3ff16c1b-f505-4355-ae1c-027f0651af24/nedexefugikiwixud.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/88e4a9bd-6910-473c-bbf8-450bafbf267c/14242657111.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fddbb846-5bcf-4878-968b-77ae0baab9ec/how_to_get_really_good_at_python.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef14724e-7834-4151-bec5-b7ee7ec24f98/zanusiwoduborejoso.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d44385a-ee80-4887-a996-f7018d9f88e5/kuwurojojepotudaje.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af829cdb-abe2-47c1-98e4-ecdc485cf8b9/30817571068.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/60ac1d7f-f630-4117-ad2d-48e54e1ebda8/sizazaxovekizem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0a15a8b-0fd1-4d35-a7a1-7b0dd662db5c/nys_common_core_standards_math_grade_1.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001002f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1002F 5632 bytes
SHA-256: 838a91309095cb778bf2957922266caf7b694f85a39f612985b3c0678a14b123
font_01_sfnt_off00011375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11375 11280 bytes
SHA-256: 03f7ec2424f0ca97bd5c3e3466dc66b26ac620cf71f026c128526e485ecede00