Malicious PDF — malware analysis report

Static analysis result for SHA-256 78131fc88917796d…

MALICIOUS

PDF

60.7 KB Created: 2020-12-20 22:41:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cf09851bb25500685a5a31935d08f569 SHA-1: 18b970b131772675c3a1de7c7354435bff4b317f SHA-256: 78131fc88917796d6fd759ef207ea260b4ee8571e63751f9f82ea7eb8c90ed88
214 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains multiple embedded URLs, with a critical heuristic firing for a malicious redirector link and another for a PDF link farm. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs. The primary attack vector appears to be redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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
  • 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://ggtraff.ru/strik?utm_term=action+truck+parts+bolingbrook+il
    • https://dutitujazekap.weebly.com/uploads/1/3/0/8/130814390/5926207.pdf
    • https://nulixedupalaz.weebly.com/uploads/1/3/0/7/130739510/fepazi.pdf
    • https://tapebosipufadiz.weebly.com/uploads/1/3/4/3/134366988/fb2b8e09044.pdf
    • https://mosuzikovadapa.weebly.com/uploads/1/3/4/6/134667275/2f2c3ca31.pdf
    • https://xodasolilixodi.weebly.com/uploads/1/3/4/8/134874129/1ab5e1ab81.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static1.squarespace.com/static/5fc6e107791da6493f66ed7c/t/5fc8167c094cf7617db25e89/1606948478878/dragon_heroes_tactics_reroll.pdf
    • https://s3.amazonaws.com/nelizenejakarug/australia_snow_report_forecast.pdf
    • https://s3.amazonaws.com/kudowo/st_martin_of_tours_franklin_wi.pdf
    • https://s3.amazonaws.com/jaburirarov/13548091788.pdf
    • https://s3.amazonaws.com/xamibudasagas/3514485046.pdf
    • https://uploads.strikinglycdn.com/files/2e257a0b-8ec3-419d-8865-9c0338005747/36840491156.pdf
    • https://s3.amazonaws.com/nazekisigiduz/95831461911.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_off0000b2cc.bin
6237cf7d16a52579f5774b2cf4e59bf90a75e13aee135b1ae1a7a9685a4ccaa8
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2CC 5292 bytes
font_01_sfnt_off0000c4dc.bin
d9b3b94649bc0aa8e32851b6c2fae480faaff8b9a8e8a042ff3dec30c5903288
pdf-font-stream PDF embedded font (sfnt) at offset 0xC4DC 9824 bytes