Malicious PDF — malware analysis report

Static analysis result for SHA-256 823b5c516f2353c1…

MALICIOUS

PDF

33.3 KB Created: 2020-08-01 02:15:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 788e32b3b5f09833da4ec101249373b0 SHA-1: 30cfe0f9e9d4e512395b051ff05ed77997bfa745 SHA-256: 823b5c516f2353c1fb5027ade834ba2f97f2e655ef2f4ee7889f4e3f740f2e73
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm and a redirector to malicious infrastructure, disguised as a solutions manual. The ML classifier strongly indicated maliciousness. The primary IOC is the redirector URL, which likely leads to a further stage of the attack.

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.cc/pify?keyword=organic+chemistry+solutions+manual+pdf+klein
    • http://files.keithcochrane.com/uploads/1/3/1/1/131163904/9866182.pdf
    • http://files.surreyhillsmusicfestival.com/uploads/1/3/0/7/130738758/d3fa4.pdf
    • http://files.mplusfphotography.com/uploads/1/3/1/3/131384568/b31586cf6f3.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0435/3651/5224/files/34418387044.pdf
    • https://cdn.shopify.com/s/files/1/0438/0629/4178/files/390203586.pdf
    • https://cdn.shopify.com/s/files/1/0433/1618/3205/files/kisijasexazivi.pdf
    • https://cdn.shopify.com/s/files/1/0431/3730/2679/files/96618242900.pdf
    • https://cdn.shopify.com/s/files/1/0430/1104/7575/files/32044957974.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/naduz.pdf
    • https://cdn.shopify.com/s/files/1/0433/5783/1326/files/fijimexaroxuwipiz.pdf
    • https://cdn.shopify.com/s/files/1/0430/2385/9873/files/wirofevititulefosex.pdf
    • https://cdn.shopify.com/s/files/1/0429/2175/4787/files/jilepexitagazi.pdf
    • https://cdn.shopify.com/s/files/1/0431/3199/4280/files/pasorubiworikozafunip.pdf
    • https://cdn.shopify.com/s/files/1/0429/9345/1159/files/tiwexalaz.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_off0000457a.bin
7196e704ad27414b7a912b2c699093f796711233841997fe58a978c7776f9fe3
pdf-font-stream PDF embedded font (sfnt) at offset 0x457A 5760 bytes
font_01_sfnt_off000058f9.bin
f3e5977adbe1ae2ec30ce6ed8b61448b8105496b78f5bdd88b83a7ce02074b04
pdf-font-stream PDF embedded font (sfnt) at offset 0x58F9 9268 bytes