Malicious PDF — malware analysis report

Static analysis result for SHA-256 85efb353e799cc38…

MALICIOUS

PDF

41.7 KB Created: 2020-08-23 09:30:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c5a5b3c91f9cda7ec2b72becc292ef21 SHA-1: ebc5c7274652fbbc8fa33ecbcc0fd224c7cbf1a8 SHA-256: 85efb353e799cc388ef828ca79940a6093e6ccc565a5ec6a288320acf46b8488
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains embedded links, one of which, 'https://ttraff.ru/pify?keyword=mensa+home+test+answers', is flagged as a malicious redirector. The document body, though heavily obfuscated, contains text related to 'Mensa home test answers', suggesting a lure. The presence of numerous other links, many pointing to Shopify, indicates a link farm strategy, likely to obscure the malicious destination. The ML classifier strongly supports the malicious verdict.

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.ru/pify?keyword=mensa+home+test+answers
    • http://files.rachaelhainswesson.com/uploads/1/3/1/3/131379099/rikuzopinafi.pdf
    • http://files.texascedarblinds.com/uploads/1/3/2/3/132303082/nusoxosaforegom_juxebabapatuni_mawirakivakixez_kaxixejowibar.pdf
    • https://cdn.shopify.com/s/files/1/0447/8582/7991/files/bodice_pattern_free.pdf
    • https://cdn.shopify.com/s/files/1/0430/1907/5737/files/54979295615.pdf
    • https://cdn.shopify.com/s/files/1/0463/5177/7954/files/17291168244.pdf
    • https://cdn.shopify.com/s/files/1/0431/5460/4198/files/xobemewepojogofepesoji.pdf
    • https://cdn.shopify.com/s/files/1/0431/8239/1451/files/antenna_theory_and_design_3rd_edition.pdf
    • https://cdn.shopify.com/s/files/1/0427/6633/6166/files/97723627096.pdf
    • https://cdn.shopify.com/s/files/1/0436/9481/7445/files/sigavujodepetuwupiruxuvaz.pdf
    • https://cdn.shopify.com/s/files/1/0432/3622/9278/files/zolepakened.pdf
    • https://cdn.shopify.com/s/files/1/0427/8976/5279/files/nujofuninoku.pdf
    • https://cdn.shopify.com/s/files/1/0432/9095/1846/files/adverb_of_frequency_worksheet_for_grade_3.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_off000063ea.bin
4962a8d1577073b61fa951a529b6c07fc1f56d4ae700ba448b22d2ac017973d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x63EA 4992 bytes
font_01_sfnt_off000074cb.bin
a51e3f9061366b77a489c2075b782bb58a6c7d36ed9b8b400d23215c2ee2bbc2
pdf-font-stream PDF embedded font (sfnt) at offset 0x74CB 11128 bytes