Malicious PDF — malware analysis report

Static analysis result for SHA-256 e81d5b88c078207a…

MALICIOUS

PDF

56.0 KB Created: 2020-07-30 10:45:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f2312c7851ea20ece70240d178abd442 SHA-1: 110317cb6acd4fd262a36a8a71b6b96bcdbca4dd SHA-256: e81d5b88c078207a968bad6950f7d84493e8faac0cd973993751cf838e72f4e5
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains multiple embedded links, with one specifically pointing to a known malicious redirector. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains text related to 'Recapitulation theory pdf' and wkhtmltopdf, suggesting a lure document. The primary attack vector appears to be redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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://ttraff.com/pify?keyword=recapitulation+theory+pdf
    • http://files.thetinyjungle.com/uploads/1/3/1/4/131406288/mofukexaxuwep-sazob.pdf
    • http://files.conditionsforlearning.com/uploads/1/3/1/4/131482950/lufumipajoset.pdf
    • http://files.richwoodsstjuderun.com/uploads/1/3/1/8/131856333/gowegubipetodo-sokule.pdf
    • http://files.tuiwalk.com/uploads/1/3/1/4/131438180/nerotem_rujej_wadivatufojatu.pdf
    • http://files.movewithmeg.co.uk/uploads/1/3/1/6/131636956/geluronofapufar.pdf
    • https://cdn.shopify.com/s/files/1/0429/9204/2137/files/51123223115.pdf
    • https://cdn.shopify.com/s/files/1/0437/9328/5277/files/17273285168.pdf
    • https://cdn.shopify.com/s/files/1/0440/8731/2536/files/53205416878.pdf
    • https://cdn.shopify.com/s/files/1/0433/2149/1621/files/23420003481.pdf
    • https://cdn.shopify.com/s/files/1/0430/8919/9268/files/20868323961.pdf
    • https://cdn.shopify.com/s/files/1/0431/8694/6206/files/60445186259.pdf
    • https://cdn.shopify.com/s/files/1/0430/6622/8898/files/12334504746.pdf
    • https://cdn.shopify.com/s/files/1/0427/4647/8759/files/fatene.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/68906731860.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/96258555683.pdf
    • https://cdn.shopify.com/s/files/1/0436/0273/9362/files/vorum.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00009e5c.bin
8d512a66630f614a5849628fb6418a414538a0f4cd3539aa854871919108f325
pdf-font-stream PDF embedded font (sfnt) at offset 0x9E5C 5056 bytes
font_01_sfnt_off0000af83.bin
bedc7f2f78793cb01b239215fa9bd019faa5d45b86c2e5e16f21a4b230e9a5e7
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF83 10308 bytes