Malicious PDF — malware analysis report

Static analysis result for SHA-256 82dfcaa38a79e296…

MALICIOUS

PDF

41.5 KB Created: 2020-10-29 22:52:07 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 82f64756a27c8524d4dda04f0e610edc SHA-1: 185ecfc42c22e521e163c30f73af86aadca52351 SHA-256: 82dfcaa38a79e29639d96011d696cd9c85f6e574e3682a9dfc13dd4f576e8fea
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one heuristic specifically identifying it as a PDF link farm. One of the linked URLs, 'https://ggtraff.ru/aws?keyword=english+aids+worksheets', is flagged as a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body appears to be obfuscated or corrupted, but the presence of the malicious URL and the link farm structure strongly suggest an attempt to redirect users to harmful content.

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://ggtraff.ru/aws?keyword=english+aids+worksheets
    • https://cdn-cms.f-static.net/uploads/4401694/normal_5f92f706cf834.pdf
    • https://pisanofinupu.weebly.com/uploads/1/3/1/4/131437881/gunokukefemo.pdf
    • https://cdn-cms.f-static.net/uploads/4369504/normal_5f8a9c05e34f0.pdf
    • https://tanifovekula.weebly.com/uploads/1/3/1/3/131379991/0d977a76ee4.pdf
    • https://dekekutema.weebly.com/uploads/1/3/4/4/134440935/6e8b3f2123c1f.pdf
    • https://cdn-cms.f-static.net/uploads/4393181/normal_5f924483377cb.pdf
    • https://siregudak.weebly.com/uploads/1/3/0/7/130738759/393e6ef58faffbe.pdf
    • https://cdn-cms.f-static.net/uploads/4375507/normal_5f8bad2c3248b.pdf
    • https://cdn-cms.f-static.net/uploads/4390684/normal_5f91d4aa059cb.pdf
    • https://danawejenig.weebly.com/uploads/1/3/4/4/134499985/c15a6.pdf
    • https://cdn-cms.f-static.net/uploads/4376621/normal_5f98912ff29c9.pdf
    • https://guburumo.weebly.com/uploads/1/3/4/3/134322172/letumexupaf.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/8265780f-542a-4736-b115-069f2ff52e59/betawud.pdf
    • https://s3.amazonaws.com/sinadi/44852330814.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_off000062c4.bin
fc04a91c004ccf79302783e2407d08b53bd95549891022cf899d9954956eda8d
pdf-font-stream PDF embedded font (sfnt) at offset 0x62C4 5200 bytes
font_01_sfnt_off00007481.bin
ba1b4448432e327d249ce63a1dde5d5896cb465f4652233aa0948ca1d72d7a47
pdf-font-stream PDF embedded font (sfnt) at offset 0x7481 10828 bytes